(a) Field
The invention relates to a liquid crystal display.
(b) Description of the Related Art
Liquid crystal displays (“LCDs”) are widely used among display devices as one type of flat panel displays. A liquid crystal display has two display panels on which field generating electrodes such as pixel electrodes and a common electrode are formed, and a liquid crystal layer that is interposed between the display panels. The liquid crystal display applies voltages to the field generating electrodes so as to generate an electric field in the liquid crystal layer. The electric field in the liquid crystal layer determines the alignment of liquid crystal (“LC”) molecules of the liquid crystal layer and thus the polarization of incident light, thereby performing image display.
Among the LCDs, a vertical alignment (“VA”) mode LCD, which aligns LC molecules such that their long axes are perpendicular to the panels in the absence of an electric field, has been developed.
In a VA mode LCD, a wide viewing angle that is an important characteristic of a display device can be realized by forming cutouts such as minute slits in the field-generating electrodes and/or forming protrusions on the field-generating electrodes. Since the cutouts and protrusions can determine the tilt directions of the LC molecules, the tilt directions can be distributed into various directions by using the cutouts and protrusions such that the reference viewing angle is widened.
Also, a method for providing a pretilt to the liquid crystal in the absence of an electric field has been developed to improve the response speed of the liquid crystal while realizing the wide viewing angle. For the liquid crystal to have the pretilt of the various directions, alignment layers having various alignment directions may be used, or the liquid crystal layer is applied with the electric field and a thermal-hardened or light-hardened material is added, and the light may be irradiated to slant the liquid crystal in predetermined directions.
On the other hand, the VA mode LCD has lower side visibility compared with front visibility, such that one pixel is divided into two subpixels and different voltages are applied to the subpixels to solve this problem.